Class 11th

Consider a rectangle ABCD having 5,7,6,9 points in the interior of the segments AB, CD, BC, DA respectively. Let α be the number of triangles having these points from different sides as vertices and β be the number of quadrilaterals having these points from different sides as vertices. Then (β-α) is equal to :

Given below are two statements:

Statement I : Both CaCl2.6H2O and MgCl2.8H2O undergo dehydration on heating.

Statement II : BeO is amphoteric whereas the oxides of other elements in the same

group are acidic.

In the light of the above statements, choose the correct answer from the options given below:

The type of pollution that gets increased during the day time and in the presence of O3 is:

In chromatography technique, the purification of compound is independent of:

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: The H-O-H bond angle in water molecule is 104.5°.
Reason R: The lone pair- lone pair repulsion of electrons is higher than the bond pair- bond pair repulsion.
In the light of the above statements, choose the correct answer from the options given below:

Which of the following is Lindlar catalyst?

Among the following, the aromatic compounds are:

Choose the correct answer from the following options:

At 25°C, 50 g of iron reacts with HCl to form FeCl?. The evolved hydrogen gas expands against a constant pressure of 1 bar. The work done by the gas during this expansion is __________ J. (Round off to the nearest integer).
[Given: R= 8.314 J mol?¹ K?¹. Assume hydrogen is an ideal gas]
[Atomic mass of Fe is 55.85u]